1. Field of the Invention
The invention generally relates to image processing and display, and specifically relates to calibrating an image for display on an image display apparatus.
2. Background of the Invention
In many applications that use a monitor, for example, medical diagnostics and industrial imaging, image resolution is very important for performing the desired task (e.g., diagnosing a disease, such as cancer, or a bone fracture in an x-ray, or determining if a machine part is acceptable or defective).
Conventionally, a video graphic array (VGA) monitor uses an aspect ratio (i.e., a width-to-height ratio of an image) of 1.3333333333:1. This aspect ratio results in an image being displayed on a monitor at one of a number of preset resolutions. The resolution of a monitor refers to the fineness of detail attainable by the monitor in producing the image. For a particular monitor, the number of dots, or pixels, is determined by the graphics mode and video adapter of the monitor, but the size of the display depends on the size and adjustment of the monitor. The resolution of a monitor is in terms of the number of dots, or pixels, displayed horizontally and vertically. The resolution of a monitor can also be provided in dots per inch (DPI), which refers to the number of dots, or pixels, that the monitor can display in a linear inch. For example, the resolution of a monitor in (dots2) could be: 640 dotsxc3x97480 dots, 800 dotsxc3x97600 dots, 1024 dotsxc3x97768 dots, 1224 dotsxc3x97918 dots, 1600 dotsxc3x971200 dots, and 2048 dotsxc3x971536 dots. Other ratios are also possible, either in landscape mode or portrait mode of the monitor. However, the aspect ratio of the monitor remains the same.
Medical monitors and high-definition television (HDTV) monitors may have aspect ratios other than 1.33333333:1 and may have other resolutions than those listed above. For example, a medical monitor may have a display resolution of 2048 dotsxc3x972048 dots at 150 DPI and an aspect ratio of 1:1. An image, displayed on a monitor having 150 DPI, has approximately 7.3% of the fineness of detail of a 35-mm film, which has a fineness of detail of approximately 2048 DPI.
Additionally, due to variations in aspect ratios, an image tailored to fit on one type of monitor may not fit exactly on another type of monitor simply by scaling the image. For example, an imaged scanned using one type of scanning device (e.g., a charge-coupled device [CCD] scanner or a digital camera) may support an aspect ratio different from that of a desired monitor. As a result, the image may be distorted when displayed on the desired monitor, and become even more distorted when the image is zoomed in and out.
It would be desirable to have a technique by which an image may be calibrated for display on monitors having different display characteristics.
It is an object of the invention to display an image on an image display apparatus without incurring distortion due to the scanning of the image by an image scanning apparatus.
It is an object of the invention to calibrate an image scanning apparatus and an image display apparatus such that an image displayed on the image display apparatus is the same size as the image, which is scanned by the image scanning apparatus.
The invention includes a method and an apparatus for calibrating an image display apparatus. The invention includes an image scanning apparatus and an image display apparatus which are calibrated such that a known image scanned by the image scanning apparatus is displayed on the image display apparatus in its actual size. Once the image scanning apparatus and the image display apparatus are calibrated, a desired image scanned at any scanning resolutin and stored in a computer-readable medium. The scanned desired image can be displayed on the image display apparatus such that a 1xc3x97(100%) zoom results in features of the displayed desired image having the same size as those in the desired image.
The invention includes a method for calibrating an image display apparatus with an image scanning apparatus comprising the steps of: determining a resolution of the image display apparatus; adjusting a resolution of the image scanning apparatus to the resolution of the image display apparatus; scanning a known image with the image scanning apparatus using a first scanning resolution to obtain a scanned known image; obtaining an overlay image of the known image; displaying the scanned known image on the image display apparatus as a displayed known image; placing the overlay image on the image display apparatus; and adjusting the image display apparatus such that the displayed known image is the same size as the overlay image.
The invention includes a method for displaying a desired image on an image display apparatus, comprising the steps of: determining a screen area of the image display apparatus; scanning the desired image using a second scanning resolution to obtain a scanned desired image, wherein the second scanning resolution is different than a first scanning resolution used to calibrate the image display apparatus; determining a new screen area for the scanned desired image; determining a fill area for the image display apparatus; and displaying both the scanned desired image as a displayed desired image and the fill area on the image displays apparatus.
The invention includes an apparatus for calibrating an image display apparatus with an image scanning apparatus, comprising: means for scanning a known image with the image scanning apparatus using a first scanning resolution of the image scanning apparatus to obtain a scanned known image; means for displaying the scanned known image on the image display apparatus using the first scanning resolution as a displayed known image; and means for adjusting the image display apparatus such that the displayed known image is an exact replica of the known image.
The invention includes an apparatus for displaying a desired image on an image display apparatus, comprising: means for determining a screen area of the image display apparatus; means scanning the desired image using a second scanning resolution to obtain a scanned desired image, wherein the second scanning resolution is different than a first scanning resolution used to calibrate the image display apparatus; means for determining a new screen area for the scanned desired image; means for determining a fill area for the image display apparatus; and means for displaying both the scanned desired image as a displayed desired image and the fill area on the image displays apparatus.
Moreover, the above objects and advantages of the invention are illustrative, and not exhaustive, of those which can be achieved by the invention. Thus, these and other objects and advantages of the invention will be apparent from the description herein, both as embodied herein and as modified in view of any variations which will be apparent to those skilled in the art.